diff --git a/common/Reflection.h b/common/Reflection.h
index 2682087e..03517ee1 100644
--- a/common/Reflection.h
+++ b/common/Reflection.h
@@ -24,6 +24,7 @@ struct Reflection {
     float rlp;
     bool observed = false;
     float S_x, S_y, S_z;
+    float partiality;
 };
 
 #endif //JFJOCH_REFLECTION_H
diff --git a/docs/CBOR.md b/docs/CBOR.md
index 3a6344d9..4e0c6735 100644
--- a/docs/CBOR.md
+++ b/docs/CBOR.md
@@ -147,6 +147,7 @@ See [DECTRIS documentation](https://github.com/dectris/documentation/tree/main/s
 | - image                    | float                | image number (present for each spot)                                                                                              |                           |          |
 | - dist_ewald               | float                | distance to Ewald sphere (present only for indexed spots)                                                                         |                           |          |
 | - rlp                      | float                | Reciprocal Lorentz and polarization corrections                                                                                   |                           |          |
+| - partiality               | float                | Partiality of the reflection                                                                                                      |                           |          |
 | spot_count                 | uint64               | Spot count                                                                                                                        |                           |          |
 | spot_count_ice_rings       | uint64               | Number of spots within identified rings (experimental)                                                                            |                           |          |
 | spot_count_low_res         | uint64               | Number of spots in low resolution (prior to filtering)                                                                            |                           |          |
diff --git a/frame_serialize/CBORStream2Deserializer.cpp b/frame_serialize/CBORStream2Deserializer.cpp
index d56ffc9b..7285d712 100644
--- a/frame_serialize/CBORStream2Deserializer.cpp
+++ b/frame_serialize/CBORStream2Deserializer.cpp
@@ -467,6 +467,8 @@ namespace {
                 r.rlp = GetCBORFloat(map_value);
             else if (key == "rp")
                 r.dist_ewald = GetCBORFloat(map_value);
+            else if (key == "partiality")
+                r.partiality = GetCBORFloat(map_value);
             else
                 cbor_value_advance(&map_value);
         }
diff --git a/frame_serialize/CBORStream2Serializer.cpp b/frame_serialize/CBORStream2Serializer.cpp
index 06027d43..e3c47f89 100644
--- a/frame_serialize/CBORStream2Serializer.cpp
+++ b/frame_serialize/CBORStream2Serializer.cpp
@@ -244,6 +244,8 @@ inline void CBOR_ENC(CborEncoder &encoder, const Reflection& r) {
     CBOR_ENC(mapEncoder, "image", r.image_number);
     CBOR_ENC(mapEncoder, "rp", r.dist_ewald);
     CBOR_ENC(mapEncoder, "rlp", r.rlp);
+    CBOR_ENC(mapEncoder, "partiality", r.partiality);
+
     cborErr(cbor_encoder_close_container(&encoder, &mapEncoder));
 }
 
diff --git a/reader/JFJochHDF5Reader.cpp b/reader/JFJochHDF5Reader.cpp
index e017a77e..985859db 100644
--- a/reader/JFJochHDF5Reader.cpp
+++ b/reader/JFJochHDF5Reader.cpp
@@ -681,6 +681,7 @@ bool JFJochHDF5Reader::LoadImage_i(std::shared_ptr<JFJochReaderDataset> &dataset
         auto int_err = source_file->ReadOptVector<float>(image_group_name + "/int_err");
         auto bkg = source_file->ReadOptVector<float>(image_group_name + "/background_mean");
         auto lp = source_file->ReadOptVector<float>(image_group_name + "/lp");
+        auto partiality = source_file->ReadOptVector<float>(image_group_name + "/partiality");
 
         if (h.size() != l.size() || h.size() != k.size() || h.size() != d.size()
             || h.size() != predicted_x.size() || h.size() != predicted_y.size()
@@ -691,6 +692,11 @@ bool JFJochHDF5Reader::LoadImage_i(std::shared_ptr<JFJochReaderDataset> &dataset
             float lp_val = 0.0;
             if (lp.size() > i && lp[i] != 0.0f)
                 lp_val = 1.0f / lp[i];
+
+            float partiality_val = 0.0f;
+            if (partiality.size() > i && partiality[i] != 0.0f)
+                partiality_val = partiality[i];
+
             Reflection r{
                 .h = h.at(i),
                 .k = k.at(i),
@@ -701,7 +707,8 @@ bool JFJochHDF5Reader::LoadImage_i(std::shared_ptr<JFJochReaderDataset> &dataset
                 .I = int_sum.at(i),
                 .bkg = bkg.at(i),
                 .sigma = int_err.at(i),
-                .rlp = lp_val
+                .rlp = lp_val,
+                .partiality = partiality_val
             };
             message.reflections.emplace_back(r);
         }
diff --git a/writer/HDF5DataFilePluginReflection.cpp b/writer/HDF5DataFilePluginReflection.cpp
index 2b9fc2e5..8f826b29 100644
--- a/writer/HDF5DataFilePluginReflection.cpp
+++ b/writer/HDF5DataFilePluginReflection.cpp
@@ -17,7 +17,7 @@ void HDF5DataFilePluginReflection::Write(const DataMessage &msg, uint64_t image_
 
     std::vector<int32_t> h, k, l;
     std::vector<float> I, sigma, d, lp;
-    std::vector<float> image, pred_x, pred_y, bkg;
+    std::vector<float> image, pred_x, pred_y, bkg, partiality;
 
     for (const auto &refl : msg.reflections) {
         image.emplace_back(refl.image_number);
@@ -31,6 +31,7 @@ void HDF5DataFilePluginReflection::Write(const DataMessage &msg, uint64_t image_
         pred_y.emplace_back(refl.predicted_y);
         bkg.emplace_back(refl.bkg);
         lp.emplace_back(1.0/refl.rlp);
+        partiality.emplace_back(refl.partiality);
     }
 
     std::string image_group_name = fmt::format("image_{:06d}", image_number);
@@ -47,6 +48,7 @@ void HDF5DataFilePluginReflection::Write(const DataMessage &msg, uint64_t image_
     image_group.SaveVector("background_mean", bkg);
     image_group.SaveVector("observed_frame", image);
     image_group.SaveVector("lp", lp);
+    image_group.SaveVector("partiality", partiality);
 }
 
 void HDF5DataFilePluginReflection::WriteFinal(HDF5File &data_file) {